The previous article in this series covered issues relating to the initial adaptation phase of PowerCranks use. This initial adaptation phase could be considered to be approximately two weeks in duration. This is the time when neurological motor patterns are developed to allow torque production around the entire 360 degrees of crank rotation. After these motor patterns have developed, the next phase of PowerCranks training could be considered to be an aerobic base development phase.

This article will document my experience of PowerCranks use in this aerobic base development phase and offer some advice to those in a similar situation. It is understood that some athletes will be commencing PowerCranks use at some other stage in their training progression and will need to adjust their PowerCranks training accordingly.

BASE PHASE POWERCRANKS TRAINING BASICS

Firstly, if you are presently undertaking a period of base training, then the general principles of base phase training are no different whether using PowerCranks or not.

The aerobic base phase can be considered a critical element of any endurance training program. The adaptations required to enhance slow twitch fibre lipid processing capability take place in this phase and the vast majority of training should be completed at or below "fat max" intensity.  At these intensities, slow twitch muscle fibre is recruited and, more importantly, lipid is processed close to it's maximal rate, providing the stimulus for slow twitch fibre lipid processing enhancement. In elite cyclists, "fat max" intensity has been shown to be in the vicinity of 79% of HR Max, but is variable within a small range, depending on the individual. Less experienced athletes are likely to have "fat max" intensity at lower relative intensities with the major influencing factors being training status and muscle fibre composition. Where this point lies in the intensity spectrum of the individual can be determined by a laboratory test.

Other fundamental aspects of fitness generally targeted in this base phase include strength and skill.

Aerobic capacity of the slow twitch fbres, strength of the prime movers and stabilising muscles and technical skill are all factors that impact on cycling economy. Economy represents the ability to exercise at a particular power output with the lowest possible oxygen cost/consumption and is considered an important factor in endurance racing success.

While base phase training principles are the same if using either PowerCranks or conventional cranks, there are some practical issues of PowerCranks use that must be addressed. For 99% of individuals, the maintennance of individual training/racing cadences will be impossible with PowerCranks. As has been described in previous articles, the upstroke musculature must work, without assistance from the downstroke musculature, to rotate the crank arm from BDC to TDC. The upstroke musculature, after being assisted by the downstroke muscular during conventional crank cycling, is unlikely to have developed a high degree of aerobic efficiency and typical pedalling cadences will result in lactate accumulation, acidosis and local muscle fatigue.

Decreasing pedalling cadence, while keeping overall power output low, reduces the metabolic demand on the upstroke musculature, allowing it to operate at the appropriate base training intensity. The good folk at PowerCranks recommend utilising a cadence in the vicinity of 70rpm and I found it to be an appropriate starting point. Keep in mind that in the initial stages, it will be difficult to maintain even 70 rpm for extended periods of time, but with perseverence, progression will come at a rapid rate.

Let cadence be your guide to adaptation, the longer you can maintain a cadence without stopping, the fitter your upstroke musculature is becoming. When a particular cadence can be maintained continuously for approximately 60 mins, it is time to progress to a higher cadence. My recommendation is to perform intermittent periods (30 - 60 secs) of pedalling cadence slightly faster (5rpm or so) than the current manageable PowerCranks training cadence in order to promote the neurological and physiological adaptations needed to become comfortable at higher cadences.

In my opinion, to get the maximum performance benefit, pedalling cadence manageable with PowerCranks should approach that which is used with conventional cranks. If normal race/TT cadence is in the 95rpm region, then 85rpm is an appropriate target PowerCranks cadence.

I found that even in the intial stages of my PowerCranks training, when I was comfortable at cadences closer to 75 rpm, there was a positive impact on my conventional crank cycling action. I was able to maintain higher cadences than prior to my PowerCranks training, indicating a positive adaptation in the aerobic capacity and coordination of my upstroke musculature. What does this really mean? Higher cadences when compared to lower cadences equate to lower muscular forces at equal power outputs. Lower forces mean less inefficient, lactate producing, fast twitch fibre recruitment and hence, at worst, a potential increase in the relative intensity at which both lactate threshold and maximal lactate steady state occur, or put another way, an increase in exercise economy.

I had no immediate race goals when I started my PowerCranks training and, as a result, could commence a base phase where I performed every ride on PowerCranks. The progression of longest ride duration I achieved is as follows, with the consideration that I performed, on average, 5 rides per week during this time:

Week 1 : 1.5 hrs, predominantly 75rpm

Weeks 2 - 3 : 1.5 - 2 hrs with some climbing,  predominantly 75rpm with periods at 80rpm

Weeks 4 - 5 : 2 - 2.5 hrs, predominantly 80rpm with periods at 85rpm

Weeks 6 - 9 : 3 hrs, 3hrs 20mins, 3 hrs 40mins, 4 hrs in subsequent weeks, all over hilly terrain, 80 - 85 rpm

If frequency of training per week is less, then progression may came at a slower rate.

The long ride is the most important session in this phase and at least 3 hrs should be targeted. The base phase traditionally lasts anywhere from 8 - 16 weeks depending on the experience of the athlete, and should be long enough for each athlete to build to a ride of three hours using PowerCranks. For those racing the Ironman distance, it would be prudent to build to a 5 hour PowerCranks ride in this phase. Additionally, it would be favourable for triathletes/time triallists to do some period of the long ride while down in the time trial position. Initially, however, it is very difficult to adopt this position while using PowerCranks as the hip/torso angle is reduced and the hip flexors move through a less biomechanically efficient range. The reduction in hip angle can be minimised by raising the level of the aerobar pads, and as adaptation occurs, the aerobar pads can be slowly lowered to their original position. You may ask the question - is it absolutely necessary to perform PowerCranks training in the time trial position? To that I would say probably not, but I have got to the stage where I can ride for three hours comfortably in the time trial position using PowerCranks, and it is great for the confidence.

As with any base development phase, steady state training intensity and duration should slowly increase during this time in preparation for the next phase of training.

In the instance of PowerCranks training, fast tracking the adaptation process of the upstroke musculature may be appropriate. This can be achieved by performing short, intense, high cadence intervals at maximal oxygen uptake intensity. For example, 30 seconds on, 30 seconds off on the stationary trainer. A four week period of these intervals twice a week is recommended for those more experienced athletes. For those less experienced, some on the bike resistance training is probably more suitable. A typical session of this type is 3 - 5 minute efforts, utilising a cadence between 45 and 65 rpm at an intensity level of just below maximal lactate steady state. Progress from higher to lower cadence and increase cadence if knee pain is an issue. This type of training can be utilised throughout the base building period.

If you are in the base phase and don't want to do every ride on Powercranks, it may not be absolutely necessary to do so. My only rock solid recommendation with regard to PowerCranks base phase training is that a 3 hour ride is the absolute minimum that should be achieved. Any athlete with ambition will find, like myself, that using PowerCranks is addictive. It is a challenge from day one , it is obvious they are of great benefit, and it will be hard not to train with them for fear of losing the gains achieved with them. Put them on and ride.

For those athletes with present and continuing racing goals, critical race specific sessions will not be possible at first using PowerCranks and this will necessitate the alternate use of conventional cranks with PowerCranks. It would be ideal to have two bikes available at this time, one set up in a road racing position with PowerCranks attached, and the other with conventional cranks for the majority of quality sessions. However, one bike will be more than acceptable, as the cranks can be changed over with the minimum of fuss.

Ideally, the use of PowerCranks is recommended at every possible opportunity - outside of critical race specific sessions. ie. use PowerCranks for all easy rides and warm ups. It must be said though, that I have heard of athletes using PowerCranks three times a week for an hour or less and still report benefits. I would also recommend replacing one of the intense conventional crank sessions with an intense PowerCranks session. The important factor here is to perform some of the PowerCranks training at TT/race cadences such that there is a positive adaptation to the specific demands of time trialling/racing. The short, intense, high cadence intervals described above would be appropriate in this instance. If a PowerCranks ride of up to 3 hours can be achieved in this period then all the better.

Arguably, one of the most important benefits for those triathletes just starting PowerCranks use in the race season, is to running performances. It may be difficult to build a significant aerobic base in the upstroke musculature at this time, but, with specific PowerCranks ride/run sessions, utilising small periods of cycling cadence that is similar to efficient running cadences, ie 90+ rpm, it is possible to develop a faster, more efficient running cadence. Regular running sessions off the bike will help to transfer the positive adaptions in the motor function of the upstroke musculature while cycling, to that of the specific movements of the running recovery action.

All PowerCranks users will benefit from isolated leg training to enhance the already high skill development stimulus that PowerCranks use provides. Low cadence, high force, efforts would be appropriate for those in the base phase while a combination of the former and higher cadence efforts, specific to time trialling/racing, would be appropriate for those in season athletes.

This is an area of particular importance to PowerCranks users. As the stable base provided by conventional cranks is no longer available, a stable core and shoulder girdle is particularly important to enhance bike handling skills and promote efficiency of movement. A stable core and shoulder girdle provide a solid platform for efficient power transfer from legs to cranks.

The stabilisers are best trained with long isometric contractions, or short range isotonic movements. An array of front, side and back lying bridging exercises are suitable exercises to promote core stability. The challenge can be increased by utilising unstable bases of support such as a swiss ball or inflatable disc.

Of extreme importance here is the development of isometric strength in those stabilisers antagonistic to the hip flexors and adductors in the range of motion specific to the stance phase of the running action. These muscles are the hip abductors and extensors and primarily consist of the gluteal group - maximus, minimus and medius. I have experienced many problems due to the weak stabilisation ability of my gluteals, and consider it a training priority for any athlete involved in running, cycling or multisport.

The strength referred to here is strength endurance, or the maximum weight that can be lifted between 12 and 20 times. Studies have shown endurance performance to improve following a strength endurance resistance training program in novice endurance athletes. Researchers have found the mechanism of improvement to be an increase in exercise economy. The theory being that strength improvement of individual muscle fibres of the prime movers and stabilisers mean fewer motor units need to be recruited to maintain a particular submaximal power output.   While it is unlikely that strength training will have any benefit to endurance performance once a certain base line level of strength is achieved, the upstroke musculature, if not previously strength trained, can be considered "inexperienced muscle" in Powercranks users and it is reasonable to suggest that strength endurance training could be beneficial from an exercise economy perspective.

The exercises most suitable are those that mimic the action of the upstroke musculature.

I hope readers find this insight helpful.

The next article will offer advice to those who feel that they may want have a go at racing on their PowerCranks. I have already raced on mine, at the Escape from Alcatraz race and will probably do a half ironman on them in the near future. I may also try them in an Ironman for the first time this August in Canada. I will see how the training is progressing.

Take care all and good luck with the training.